Merge pull request #2900 from jimmyjones2/sub_agg

Metric aggs are never sub-aggs

src/kibana/plugins/visualize/editor/agg_select.html

@@ -1,6 +1,6 @@
 <div class="form-group">
-  <label ng-if="$index < 1">Aggregation</label>
-  <label ng-if="$index >= 1">Sub Aggregation</label>
+  <label ng-if="$index < 1 || groupName !== 'buckets'">Aggregation</label>
+  <label ng-if="$index >= 1 && groupName === 'buckets'">Sub Aggregation</label>
   <select
     name="agg"
     class="form-control"
@@ -8,4 +8,4 @@
     required
     ng-options="agg as agg.title for agg in aggTypeOptions | aggFilter:agg.schema.aggFilter">
   </select>
-</div>
+</div>